How to stop Hum from a Flat Panel monitor?

[Swaphappy]

I think what I am going to try is
to place the DAW in another room
not connected to any thing but a guitar
and head phones and see what I get.
If I still get the hum them it must be
a bad monitor.
If not then it might be ground looping or
cross talk.
What do you think?

[Swaphappy]

Anyone experience this?
I bought a new Dell 1702fp flat panel monitor.
Electric instruments seem to pick up a low frequency hum or buzz from the monitor.
With the old CRT monitor I was getting a little
hiss.
The hum goes away if I turn the monitor off.
Any idea what I can do about it beside getting rid of the hardware?

Take a listen to this sound clip of the HUM:Sound-Test.mp3 (http://filebox.vt.edu/users/merc/FHS/Sound-Test.mp3)

[mattm]

assuming it's an LCD display, i'd be inclined to contact Dell about it.

there's been many an occasion i've had to turn off a CRT monitor when a guitar (especialy one with single coil pick-up) was nearby, particuarlly behind it due to EMR, but i have never encountered this problem with an LCD display.

also check that you have not inadvertantly created an earth loop with the new device.

~matt

[yavuzj]

Originally posted by Swaphappy:
Anyone experience this?
I bought a new Dell 1702fp flat panel monitor.
Electric instruments seem to pick up a low frequency hum or buzz from the monitor.
With the old CRT monitor I was getting a little
hiss.
The hum goes away if I turn the monitor off.
Any idea what I can do about it beside getting rid of the hardware?<font size="2" face="Verdana, Arial">Could it be that your LCD displays electric connection is causing a ground loop?
I know everyone is bragging about their LCD being quiet so this makes me curious. images/icons/confused.gif

[Swaphappy]

The flat panel(LCD) monitor could be bad but then again I get a similar problem with the CRT monitor except that it is hiss instead of hum.
Ground looping could be it.
What is the best way to avoid ground looping?
I have every thing plugged into one outlet now, but the computer and monitor are on a power strip that is plugged into the same outlet.
Perhaps I should unplug everything and start over with just the DAW computer and monitor (No mixer or or monitor amp).

Thanks for the replies BTW.

[yavuzj]

Did you try seperating your audio and electric cables as far as possible????

[Swaphappy]

The outlet expander that I am using is one of those modern ones which has the 3rd wire ground on
all outlets.
No ground pins are broken off to my knowledge unless it is an internal open.
The outlet expander also has two indicator lights on it that are showing a good ground and good power.
Not sure if grounding is a problem.

[Shannon Dunn]

You definitely should not be getting a buzz from an LCD monitor. If the buzz increases as you move to the monitor, then I would return the monitor. A ground loop should cause the humming problem regardless of where you stand in the room. If the hum is localized to the monitor, then it's a bad monitor. Or, it could be that you're actually picking up hum from the speaker monitors, or perhaps some other source that's close to the LCD. Perhaps you are associating it with the LCD, but it's actually proximity to some other device near the LCD that's actually causing the hum. I would check on that. I have a spot in my studio where no guitarist can stand to play, cause it picks up rf from that spot. I believe it has to do with a copper water pipe directly overhead. My theory is that the house piping system picks up the rf and standing under that pipe is like hooking up to a big antenna. Of course, I could be wrong. It could simply be a directional issue, or line of sight issue to a tower somewher. But that's my crazy theory and I'm sticking to it.

[Swaphappy]

Originally posted by Shannon Dunn:
I have a spot in my studio where no guitarist can stand to play, cause it picks up rf from that spot. I believe it has to do with a copper water pipe directly overhead. My theory is that the house piping system picks up the rf and standing under that pipe is like hooking up to a big antenna<font size="2" face="Verdana, Arial">Copper pipe?
You know there might be something to that. The whole house has copper pipe here. Also there is a bathroom right above the studio and copper water pipe running down the wall less than 2 feet from the monitor. I will have to try moving some things around.

Thanks

P.S.
Take a listen to this sound clip of the HUM:Sound-Test.mp3 (http://filebox.vt.edu/users/merc/FHS/Sound-Test.mp3)

[Travis Mitchell]

Would a DI box with ground lift work?

[Swaphappy]

Ok, I plead ignorant on the DI box. What is it?
(Are you talking about the Digi I/O?)
I haven't tried lifting the ground yet.
Are you saying I should lift the ground on the flat panel monitor only? Hoping to break a possible ground loop?

BTW, I took the setup (DAW and Mackie) upstairs
to a room close to the main breaker panel and tried an outlet there. There was no hum in that location even with the guitar volume on full and the Mackie fader up all the way.
When I placed everything down stairs again
the problem hum was there again.

Still puzzled but I'm getting closer to a solution. May be the outlet I am using is just to far from the earth ground and the ground is floating because of resistance in the wiring.
Still guessing at this point.

[bmueller]

Originally posted by mattm:
the easiest (and most dangerous) way to lift the ground is to purchase a device that allows you to connect two devices to the same outlet.*

break off the ground pin and connect your new monitor to this outlet and see what happens*

*no responsibility will be taken for lack of electrical knowledge.<font size="2" face="Verdana, Arial">NEVER (and I know what I say) NEVER break of any ground pins!!

Because the ground is your life insurance! You wouldn´t be the first guitar player, that died on electric shock!

The problem with your guitar that pics up noise from other devices is propably the shielding. Ether the cable is bad (I have to say that the price has nothing to do with quality...) or even the guitar. Try somthing else: Take a microfon and connect it to your Digi01 with a symmetric cable (XLR). If you dont have the problem, it was the cable or the guitar. If you still have it, it could be the monitor or (what seems more possible to me) the DIGI!

Greetings!

[bmueller]

I see your other posting, now. So it seems to be the guitar or the cable. Often the cables ar bad, try one with good shielding (often thick and unflexible....).

There are also DI-"Boxes" you can put direct in the guitar outlet and then use a symmetric microphone cable. But the most giutar amplifiers don´t hav symmetric inputs, so you would have to go direct in the 001.

The guitars itself are often bad shielded to. Try recording without a hand on the sites. If the problem gets worse, your guitar ist very bad shilded. That a problem sombody with good guitar / electrical experience could propably change.
It could be the pick ups to, if they are single coil. some changes in the guitar (blind coil) could fix this to, but they´ll change the sound a bit.

Greetings,

Boris

[Swaphappy]

I think it was the external power supply (power adapter) for the Dell 1702fp flat panel monitor that was causing the HUM in the audio.
After moving the DAW back down stairs I switched the power adapter with one from another monitor and the HUM went away.

I still had a little white noise or static however. Fixed the static noise by connecting a ground wire from the Digi 001 I/O box to the frame of the Mackie mixer.

Now I am in pretty good shape noise wise.
I cranked up everything full vol and still had virtually no noise. images/icons/smile.gif